Subject wise Technical Mechanical Interview Questions By S k Mondal

Technical Questions Subject wise
Type of technical questions asked will be from basics. Your favorite subjects will be asked and they start from there.

Strength of Materials

What do you mean by uniform strength in a beam?
What is difference between pure shear and simple (normal) shear?
Is it possible that decrease in area gives a decrease in stress?
Whether shear stresses are always parallel to shear forces?
By which experiment, you find it toughness of material.
Distinguish between direct stress & bending stress.
What do you mean by Torsional rigidity & lateral rigidity?
Define “slenderness ratio”. How it is used in long and short column?

Machine Design

What are rolling contact bearing?
What are the antifriction bearings?
What is stress concentration factor?
What is the bolt of uniform strength?
What is the difference Static Load carrying capacity & Dynamic Load carrying capacity?
Why we are not using the unit joule for torque instead of N-m.
What is Low cycle fatigue failure and High cycle fatigue failure? What are considerations of these while designing a machine?
What is mechanical advantage?
How trains take turns though there is no differential gear?
Do you know epicyclical gear box? What is the practical application of epicyclical gear box?
What is tooth profile? Which one is better?

Theory of Machines

What is keneddy theorem?
What is defect in Davis steering gear?
Do we need a screw with efficiency less than 50%?
What is backlash?
What is damping ratio?
Define Resonance.
Define critical speed or whirling speed or whipping speed.
What is machine? Giving example, Differentiate between a machine & structure.
What is Mechanical advantage.

subjectwise technical mechanical interview questions

Thermodynamics

What is availability function for a closed system?
If it is possible that entropy of a system can decrease during a given process?
What is dead state in thermodynamics?
What is energy?
What happens to triple point line when projected to P-T plane?
What is compressibility factor and what is its value for Vander walls gases.
What are initial conditions for formation of shock waves?
What do you understand by choking in nozzle flows?
Is it possible that pressure and velocity decreases simultaneously/
Distinguish between “Available energy” & Availability?
What is pure substances.
What is critical point? What is the value f critical temperature, pressure & volume of water?
What is sublimation curve, fusion curve & vaporization curve?
What is Rayleigh Line & Fanno Line?
What is normal shocks & when its occurs?
What is High Grade Energy & Low Grade Energy?

Fluid Mechanics and Fluid Machinery

What is the difference between impulse & reaction turbine.
Explain unit speed, unit discharge unit power & specific speed.
Explain NPSH, in which parameter it depends on.
What is jet ratio?
What is Deriaz turbine?
Which turbine is good for tidal power plant?
What is Navier-stroke equation.
What are the significance of
Mach number
Weber number

Heat & Mass Transfer

What is Newton’s Law of cooling.
What is Recuperator & Regenerators?
Whether fin can actually reduce heat transfer? is it possible? When?
What is difference between Biot no. & Nusselt no?
Which one is greater, thermal boundary layer or hydrodynamic boundary layer?
What is film temperature in forced convection flow?
What is fully developed region and where it is applicable?
What is the critical radius of insulation, explain clearly in terms of thermal resistance and heat transfer rate?
At what case do you recommend Fin?
What is the difference between free convection & forced convection in what parameter forced & free convection depend.

Internal Combustion Engine

What is the use of Carburetor in SI Engine, There is trend towards increases of injection system in Automobiles, Explain.
Why Supercharging is not popular with SI Engines?
What is performance number.
Explain Knocking in SI Engine & Mention, the factor that tend to reduce Knocking?
Explain the difference between Knocking in SI Engine & CI Engine?
How does “Turbulence” differ from “Swirl”?
Name some Antiknock additive and explain the Mechanism by which they reduce the knock?

Power Plant Engineering

What is slip ratio in thermal power plant?
In Pendant super heater whether parallel flow or counter flow heat exchange between steam and flue gases.
What happens to mass flow in case of supersatured flow?
Why clearance are provided in reciprocating compressor?
Explain turbojet & Rocket Engine.
What’s the advantage of compounding of steam turbine?
What’s are boiler mounting & accessory.
Draw the sketch of pulse jet engine. What are its main advantage & disadvantage?
Explain working principal of scram jet engine, what is advantage over the ramjet?
What are the advantage of nuclear power plants over thermal power plants.
What is fast breeder reactor?
What is circulation ratio and what is its range in power plant?
One 2-row Curtis turbine is equivalent to how many reaction turbines for same value of blade velocity and angle of nozzle?
What are thermal neutrons?
What is breeding ratio?
What is the application of jet and rocket technology? Which is used in missiles?

Refrigeration and Air-conditioning

What is utility of comfort chart?
What is wet compression?
To maximize COP what should be the condition of vapour at suction to compression?
What is the range of NBP (normal boiling point) in case of most refrigerants?
Why COP of CO2 gas is less and still why it is used in transport refrigeration?
What are the most crucial parts in reciprocating compressors?
How compressors are selected based on type of refrigerant?
What is correlation between wet bulb temperatures an adiabatic saturation temperature?
Why isothermal compressor is Desirable?
What is desirable property of ideal refrigerant?
Define effective temperature & what is the optimum design condition for comfort for summer A/C?

Production Engineering

Why arc is slowly extinguished in case of arc welding?
Which inert gas is commonly used for thin work piece and which inert gas for thick work piece?
What is friction welding?
What is difference between brazing & braze welding?
Why hole basis system is adopted in manufacturing?
What is 3- 2-1 principle?
Where diamond pin locator is used?
How presses are rated?
What is spring back?
What is difference between fillet and corner radius?
What are overhead costs?
Why depreciation is to be taken into account in industrial management?
Why breakeven point is important in any industry?
What is sine bar?
What is marginal cost and marginal revenue?
What is shear and where it is provided in case of punching and blanking?
What is angle of bite?
What is extrusion ratio?
What is gutter and where it is used?
Which process is used for making nuclear reactor fuel rods?
What is difference between Amorphous and crystalline solids?
What are the various method of inspection of casting for internal & external defects?
Why are allowances provided for in the production of patterns? What do they depend on?
What is the deference between soldering & brazing?
What is meant by solid-state welding explain.
What is cold welding?
Describe the principal behind resistance welding processes.
What function should a lubricant perform in manufacturing process?
Explain the difference between punching & blanking.
Explain the difference between discontinuous chips and segment chips.
Explain the different type of tool wear.
What is difference between oblique & orthogonal cutting.
What are the main difference between jig and fixture?
What is AOQ
What is LTPD
What is Producer risk
What is Consumer’s risk
What is JIT approaches?
What is group technology? What are its main advantages?
Define the term “production & productivity.
What is the significance of ISO 9000 series & 1400 series.
What is artificial intelligence?

Material Science

What is quazi-crystal?
What do you understand by a free cutting steel? What elements are usually added to make a steel free cutting, & how they make the steel free cutting?
Explain various method of hardening of steel?
What do you understand by the term “Arrest point” in connecting with heat treatment of plain carbon steel?
What influence does grain size have on the mechanical properties of metals.
Describe the difference between brittle and ductile fracture.
What is the difference between natural & artificial aging?